package com.hmdp.lock;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Component;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @author 大忽悠
 * @create 2022/4/29 9:37
 */
public class SimpleRedisLock implements Ilock{
    private String name;
    private StringRedisTemplate stringRedisTemplate;
    private static final String KEY_PREFIX="lock:";
    private static final String ID_PREFIX= UUID.randomUUID().toString(true)+"-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    static {
       UNLOCK_SCRIPT=new DefaultRedisScript<>();
       UNLOCK_SCRIPT.setLocation(new ClassPathResource("delLock.lua"));
       //设置脚本返回结果
       UNLOCK_SCRIPT.setResultType(Long.class);
    }

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }


    @Override
    public boolean tryLock(long timeSec) {
        //获取线程编号
        String threadId = ID_PREFIX+Thread.currentThread().getId();
       //获取锁
        Boolean success = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId + "", timeSec, TimeUnit.SECONDS);
        //success可能为null,这样拆箱过程会报错
        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unLock() {
        stringRedisTemplate.execute(UNLOCK_SCRIPT, Collections.singletonList(KEY_PREFIX + name),ID_PREFIX+Thread.currentThread().getId());
    }
}
